Britain's Duchess of York was caught on camera by a newspaper apparently offering to sell access to her ex-husband and UK trade envoy Prince Andrew and said she had been "devastated" by the story.

According to footage on the News of the World's website published on Sunday, Sarah Ferguson appears to ask for $40,000 in cash and GBP500,000 ($718,500) by wire transfer, claiming she could introduce the undercover reporter to the prince.

"She is devastated by the story and deeply regrets the situation and any embarrassment it has caused," Ferguson's spokeswoman told Reuters, when asked for reaction from the duchess, known as "Fergie" and no stranger to controversy.

The News of the World said the prince, the second son of Queen Elizabeth and fourth in line to the throne, knew nothing about Ferguson's claims. Buckingham Palace was not available to comment on the footage.

In the tape filmed on Tuesday, flame-haired Ferguson, over wine and a cigarette, makes it clear that her former husband "never does accept a penny for anything".

The sting, by a well-known tabloid reporter, is nonetheless likely to cause embarrassment for Andrew and the royal family.

"Five hundred thousand pounds when you can, to me ... open doors," she said in the film the newspaper said was shot at a London apartment, before shaking hands with the reporter who had posed as a wealthy businessman.

"Then you open up all the channels whatever you need, whatever you want ... We can do so much."

The 50-year-old prince, also known as the Duke of York, acts as Britain's special representative for international trade and investment, augmenting work by the business ministry.

Royal protocol

"Fergie" arrived like a breath of fresh air on the sedate royal scene in 1986 as a confident career-minded woman determined to live life to the full. But she made enemies by refusing to let royal protocol get in the way of a good time.

She said on the eve of the wedding she was "not the sort of woman who is going to meekly trot along beside her husband".

The pair, who have two daughters, divorced amicably in 1996 after a ten-year marriage.

A remote descendent of King Charles II, she was one of Andrew's childhood playmates and her father Major Ronald Ferguson was polo manager to Prince Charles, heir to the throne.

She was herself the child of a broken marriage.

Romance bloomed after Princess Diana, wife of Prince Charles, suggested Sarah as an escort for Andrew at Queen Elizabeth's annual house party in Windsor Castle.

While Ferguson, also 50, never achieved the worldwide fame of the late Diana, she found popularity in the United States and beyond, through a variety of television appearances, penning weight loss books and charity work.

However, her New York-based promotional company Hartmoor folded last year.

The duchess was expected to pick up an award in Los Angeles on Sunday night for her work with underprivileged children at an awards ceremony organised by children's charity Variety. – Reuters